THE NEW WOULD MONKEYS
The External Ears.—Pocock (172) has shown that the auricles are useful for taxonotnic purposes, and his paper should be referred to for details. In the Hapalidae the pinna is very hairy, but it is more or less naked in the Cebidae. Of the latter Cebus has an ear which can be regarded as typical. The tragus is
FIG. 8,—A, right hand of Ateles paniscits, from below; B, right foot
of the same, x j. (Pocock.)
small, the antitragus is large and prominent and between them there is a well-marked incisura inter-tragica. There is also a deep notch between the antitragus in front and the antihelix behind; and the latter is bifid above. The lower of the two divisions of the antihelix forms the supratragus. The upper part of the margin of the pinna is folded. No lobule is present.